Zoom lens system, interchangeable lens apparatus and camera system

ABSTRACT

A zoom lens system is provided that includes a compactly constructed focusing lens unit and that has a suppressed change in the image magnification at the time of movement of a focusing lens unit. The zoom lens system according to the present invention, in order from an object side to an image side, comprises: a first lens unit having positive optical power; a second lens unit having negative optical power; a third lens unit having positive optical power; and an aperture diaphragm. At the time of zooming, the zoom lens system moves the first to third lens units so that intervals between these lens units vary. At the time of focusing from an infinity in-focus condition to a close-point object in-focus condition, the zoom lens system moves the third lens unit to the object side.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a zoom lens system and, in particular,to a zoom lens system suitable for an imaging lens system employed in aninterchangeable lens apparatus in a so-called interchangeable-lens typedigital camera system (simply referred to as a “camera system”, in somecases hereinafter). Further, the present invention relates to aninterchangeable lens apparatus and a camera system that employ this zoomlens system.

2. Description of the Background Art

In recent years, interchangeable-lens type digital camera systems arespreading rapidly. Such an interchangeable-lens type digital camerasystem has: a camera body employing an image sensor composed of a CCD(Charge Coupled Device), a CMOS (Complementary Metal-OxideSemiconductor) or the like; and an interchangeable lens apparatusemploying an imaging lens system for forming an optical image on thelight receiving plane of the image sensor. Zoom lens systems applicableto such a camera system are disclosed in Japanese Laid-Open PatentPublication Nos. 2005-284097, 2005-352057, 2006-221092, 2005-316396,2006-267425, 2007-219315, 2008-3195 and 2008-15251.

On the other hand, camera systems are known that have the function(referred to as a “live view function”, hereinafter) of displaying imagedata acquired by a shooting lens system and an image sensor onto adisplay apparatus such as a liquid crystal display in the camera body(e.g., Japanese Laid-Open Patent Publication Nos. 2000-111789 and2000-333064).

In the camera systems described in Japanese Laid-Open Patent PublicationNos. 2000-111789 and 2000-333064, focusing operation is performed by acontrast AF method when the live view function is active. The contrastAF indicates focusing operation performed on the basis of a contrastvalue of image data outputted from the image sensor. The operation ofcontrast AF is described below.

First, a camera system oscillates a focusing lens unit in optical axisdirections at a high speed (referred to as “wobbling”, hereinafter) soas to detect the direction of deviation from an in-focus condition.After the wobbling, the camera system detects a signal component in aparticular frequency band of the image region from the output signal ofthe image sensor, and then calculates the optimal position for thefocusing lens unit that realizes an in-focus condition. After that, thecamera system moves the focusing lens unit to the optimal position, sothat the focusing operation is completed. When focusing operation is tobe performed continuously in the case of shooting a video or the like,the camera system repeats this series of operation.

In general, for the purpose of avoiding uneasiness that could be causedby flicker and the like, displaying of a video is performed at a highspeed approximately of 30 frames per second or the like. Thus,basically, video image taking in the interchangeable-lens type digitalcamera system need also be performed at 30 frames per second.Accordingly, the focusing lens unit need be driven at a high speed of 30Hz at the time of wobbling.

Nevertheless, when the focusing lens unit is heavier, a motor or anactuator of larger size is necessary for moving the focusing lens unitat a high speed. This causes a problem that the lens barrel has anexcessively large outer diameter. Then, in each of the zoom lens systemsdescribed in the above-mentioned patent documents, the focusing lensunit is hardly of light weight.

Further, it should be noted that in interchangeable-lens type digitalcamera systems, the size of the image corresponding to a photographicobject varies in association with wobbling. The variation in the size ofthe image is caused mainly by the fact that the movement of the focusinglens unit in the optical axis directions generates a change in the focallength of the entire lens system. Then, when a large change in the imagetaking magnification is generated in association with wobbling, theperson who takes an image feels uneasiness.

SUMMARY OF THE INVENTION

An object of the present invention is to provide: a zoom lens systemthat includes a compactly constructed focusing lens unit and that has asuppressed change in the image magnification at the time of movement ofa focusing lens unit; and an interchangeable lens apparatus and a camerasystem that employ this zoom lens system.

The zoom lens system according to the present invention, in order froman object side to an image side, comprises: a first lens unit havingpositive optical power; a second lens unit having negative opticalpower; a third lens unit having positive optical power; and an aperturediaphragm. At the time of zooming, the first lens unit, the second lensunit and the third lens unit move so that intervals between these lensunits vary. At the time of focusing from an infinity in-focus conditionto a close-point object in-focus condition, the third lens unit moves tothe image side.

The interchangeable lens apparatus according to the present inventioncomprises: a zoom lens system described above; and a camera mountsection connected to a camera body provided with an image sensor forreceiving an optical image formed by the zoom lens system and thenconverting the optical image into an electric image signal.

The camera system according to the present invention comprises: aninterchangeable lens apparatus that includes the zoom lens systemdescribed above; and a camera body that is connected to theinterchangeable lens apparatus via a camera mount section in anattachable and detachable manner and that includes an image sensor forreceiving an optical image formed by the zoom lens system and thenconverting the optical image into an electric image signal.

According to the present invention, a zoom lens system that includes acompactly constructed focusing lens unit and that has a suppressedchange in the image magnification at the time of movement of a focusinglens unit, an interchangeable lens apparatus and a camera system thatemploy this zoom lens system can be provided.

These and other objects, features, aspects and effects of the presentinvention will become clearer on the basis of the following detaileddescription with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 1 (Example 1);

FIG. 2 is a longitudinal aberration diagram showing an infinity in-focuscondition of a zoom lens system according to Example 1;

FIG. 3 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 1;

FIG. 4 is a lateral aberration diagram in a basic state where image blurcompensation is not performed and in an image blur compensation state ata telephoto limit of a zoom lens system according to Example 1;

FIG. 5 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 2 (Example 2);

FIG. 6 is a longitudinal aberration diagram showing an infinity in-focuscondition of a zoom lens system according to Example 2;

FIG. 7 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 2;

FIG. 8 is a lateral aberration diagram in a basic state where image blurcompensation is not performed and in an image blur compensation state ata telephoto limit of a zoom lens system according to Example 2;

FIG. 9 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 3 (Example 3);

FIG. 10 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 3;

FIG. 11 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 3;

FIG. 12 is a lateral aberration diagram in a basic state where imageblur compensation is not performed and in an image blur compensationstate at a telephoto limit of a zoom lens system according to Example 3;

FIG. 13 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 4 (Example 4);

FIG. 14 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 4;

FIG. 15 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 4;

FIG. 16 is a lateral aberration diagram in a basic state where imageblur compensation is not performed and in an image blur compensationstate at a telephoto limit of a zoom lens system according to Example 4;

FIG. 17 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 5 (Example 5);

FIG. 18 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 5;

FIG. 19 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 5;

FIG. 20 is a lateral aberration diagram in a basic state where imageblur compensation is not performed and in an image blur compensationstate at a telephoto limit of a zoom lens system according to Example 5;

FIG. 21 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 6 (Example 6);

FIG. 22 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 6;

FIG. 23 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 6;

FIG. 24 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 7 (Example 7);

FIG. 25 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 7;

FIG. 26 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 7;

FIG. 27 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 8 (Example 8);

FIG. 28 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 8;

FIG. 29 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 8;

FIG. 30 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 9 (Example 9);

FIG. 31 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 9;

FIG. 32 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 9;

FIG. 33 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 10 (Example 10);

FIG. 34 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 10;

FIG. 35 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 10;

FIG. 36 is a lens arrangement diagram showing an infinity in-focuscondition of a zoom lens system according to Embodiment 11 (Example 11);

FIG. 37 is a longitudinal aberration diagram showing an infinityin-focus condition of a zoom lens system according to Example 11;

FIG. 38 is a longitudinal aberration diagram showing a close-pointin-focus condition of a zoom lens system according to Example 11; and

FIG. 39 is a block diagram of a camera system according to Embodiment12.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Each of FIGS. 1, 5, 9, 13, 17, 21, 24, 27, 30, 33 and 36 shows a zoomlens system in an infinity in-focus condition.

In each Fig., part (a) shows a lens configuration at a wide-angle limit(in the minimum focal length condition: focal length f_(W)), part (b)shows a lens configuration at a middle position (in an intermediatefocal length condition: focal length f_(M)=√(f_(W)*f_(T))), and part (c)shows a lens configuration at a telephoto limit (in the maximum focallength condition: focal length f_(T)). Further, in each Fig., each bentarrow located between part (a) and part (b) indicates a line obtained byconnecting the positions of each lens unit respectively at a wide-anglelimit, a middle position and a telephoto limit. In the part between thewide-angle limit and the middle position and the part between the middleposition and the telephoto limit, the positions are connected simplywith a straight line, and hence this line does not indicate actualmotion of each lens unit. Moreover, in each Fig., an arrow imparted to alens unit indicates focusing from an infinity in-focus condition to aclose-object in-focus condition. That is, the arrow indicates the movingdirection at the time of focusing from an infinity in-focus condition toa close-object in-focus condition.

Further, in FIGS. 1, 5, 9, 13, 17, 21, 24, 27, 30, 33 and 36, anasterisk “*” imparted to a particular surface indicates that the surfaceis aspheric. In each Fig., symbol (+) or (−) imparted to the symbol ofeach lens unit corresponds to the sign of the optical power of the lensunit. Further, in each Fig., the straight line located on the mostright-hand side indicates the position of the image surface S.

Embodiment 1

The zoom lens system according to Embodiment 1, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a fourth lens unit G4having positive optical power, and a fifth lens unit G5 having positiveoptical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a bi-convex sixth lens element L6; and a negative meniscus seventhlens element L7 with the convex surface facing the image side. Theobject side surface of the fourth lens element L4 is aspheric.

The third lens unit G3, in order from the object side to the image side,comprises: a negative meniscus eighth lens element L8 with the convexsurface facing the object side; and a bi-convex ninth lens element L9.The eighth lens element L8 and the ninth lens element L9 are cementedwith each other. The image side surface of the ninth lens element L9 isaspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises a bi-convex tenth lens element L10, a bi-convex eleventhlens element L11, and a bi-concave twelfth lens element L12. Theeleventh lens element L11 and the twelfth lens element L12 are cementedwith each other.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex thirteenth lens element L13; a bi-concavefourteenth lens element L14; a bi-convex fifteenth lens element L15; anda negative meniscus sixteenth lens element L16 with the convex surfacefacing the image side. The fifteenth lens element L15 and the sixteenthlens element L16 are cemented with each other. The object side surfaceof the fourteenth lens element L14 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase, and the intervalbetween the fourth lens unit G4 and the fifth lens unit G5 shoulddecrease. The aperture diaphragm A moves to the object side togetherwith the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Further, for the purpose of compensation of image blur caused byvibration applied to the entire system, the fourth lens unit G4 moves ina direction perpendicular to the optical axis.

Embodiment 2

The zoom lens system according to Embodiment 2, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a lens unit G4A havingnegative optical power, a lens unit G4B having negative optical power,and a fifth lens unit G5 having positive optical power. The lens unitsG4A and G4B constitute a fourth lens unit G4.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other with an adhesive layer in between.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a positive meniscus sixth lens element L6 with the convex surfacefacing the object side; and a positive meniscus seventh lens element L7with the convex surface facing the object side. The fifth lens elementL5 and the sixth lens element L6 are cemented with each other with anadhesive layer in between. The object side surface of the seventh lenselement L7 is aspheric.

The third lens unit G3 is composed of a bi-convex eighth lens elementL8. The two surfaces of the eighth lens element L8 are aspheric.

The lens unit G4A, in order from the object side to the image side,comprises a bi-convex ninth lens element L9 and a bi-concave tenth lenselement L10. The ninth lens element L9 and the tenth lens element L10are cemented with each other with an adhesive layer in between.

The lens unit G4B is composed of a bi-concave eleventh lens element L11.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex twelfth lens element L12; a positive meniscusthirteenth lens element L13 with the convex surface facing the imageside; a negative meniscus fourteenth lens element L14 with the convexsurface facing the image side; and a bi-convex fifteenth lens elementL15. The thirteenth lens element L13 and the fourteenth lens element L14are cemented with each other with an adhesive layer in between. The twosurfaces of the twelfth lens element L12 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the lens unit G4A should increase, and the interval betweenthe lens unit G4B and the fifth lens unit G5 should decrease. Theaperture diaphragm A moves to the object side together with the lensunit G4A.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Further, for the purpose of compensation of image blur caused byvibration applied to the entire system, the lens unit G4B moves in adirection perpendicular to the optical axis.

Embodiment 3

The zoom lens system according to Embodiment 3, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a lens unit G4A havingnegative optical power, a lens unit G4B having negative optical power,and a fifth lens unit G5 having positive optical power. The lens unitsG4A and G4B constitute a fourth lens unit G4.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other with an adhesive layer in between.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a positive meniscus sixth lens element L6 with the convex surfacefacing the object side; and a positive meniscus seventh lens element L7with the convex surface facing the object side. The fifth lens elementL5 and the sixth lens element L6 are cemented with each other with anadhesive layer in between. The object side surface of the seventh lenselement L7 is aspheric.

The third lens unit G3 is composed of a bi-convex eighth lens elementL8. The two surfaces of the eighth lens element L8 are aspheric.

The lens unit G4A, in order from the object side to the image side,comprises: a positive meniscus ninth lens element L9 with the convexsurface facing the object side; and a negative meniscus tenth lenselement L10 with the convex surface facing the object side. The ninthlens element L9 and the tenth lens element L10 are cemented with eachother with an adhesive layer in between.

The lens unit G4B is composed of a planer-concave eleventh lens elementL11 with the concave surface facing the object side.

The fifth lens unit G5, in order from the object side to the image side,comprises a bi-convex twelfth lens element L12, a bi-convex thirteenthlens element L13, a bi-concave fourteenth lens element L14 and abi-convex fifteenth lens element L15. The thirteenth lens element L13and the fourteenth lens element L14 are cemented with each other with anadhesive layer in between. The two surfaces of the twelfth lens elementL12 are aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the lens unit G4A should increase, and the interval betweenthe lens unit G4B and the fifth lens unit G5 should decrease. Theaperture diaphragm A moves to the object side together with the lensunit G4A.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Further, for the purpose of compensation of image blur caused byvibration applied to the entire system, the lens unit G4B moves in adirection perpendicular to the optical axis.

Embodiment 4

The zoom lens system according to Embodiment 4, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a fourth lens unit G4having negative optical power, and a fifth lens unit G5 having positiveoptical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other with an adhesive layer in between.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a positive meniscus sixth lens element L6 with the convex surfacefacing the object side; and a positive meniscus seventh lens element L7with the convex surface facing the object side. The fifth lens elementL5 and the sixth lens element L6 are cemented with each other with anadhesive layer in between. The object side surface of the seventh lenselement L7 is aspheric.

The third lens unit G3 is composed of a bi-convex eighth lens elementL8. The two surfaces of the eighth lens element L8 are aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises a bi-convex ninth lens element L9 and a bi-concave tenthlens element L10. The ninth lens element L9 and the tenth lens elementL10 are cemented with each other with an adhesive layer in between.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex eleventh lens element L11; a positive meniscustwelfth lens element L12 with the convex surface facing the image side;a bi-concave thirteenth lens element L13; and a bi-convex fourteenthlens element L14. The twelfth lens element L12 and the thirteenth lenselement L13 are cemented with each other with an adhesive layer inbetween. The two surfaces of the eleventh lens element L11 are aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase, and the intervalbetween the fourth lens unit G4 and the fifth lens unit G5 shoulddecrease. The aperture diaphragm A moves to the object side togetherwith the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Further, for the purpose of compensation of image blur caused byvibration applied to the entire system, the fourth lens unit G4 moves ina direction perpendicular to the optical axis.

Embodiment 5

The zoom lens system according to Embodiment 5, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a fourth lens unit G4having negative optical power, and a fifth lens unit G5 having positiveoptical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a positive meniscus sixth lens element L6 with the convex surfacefacing the object side; and a positive meniscus seventh lens element L7with the convex surface facing the object side. The fifth lens elementL5 and the sixth lens element L6 are cemented with each other with anadhesive layer in between. The object side surface of the seventh lenselement L7 is aspheric.

The third lens unit G3 is composed of a bi-convex eighth lens elementL8. The two surfaces of the eighth lens element L8 are aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises a bi-convex ninth lens element L9 and a bi-concave tenthlens element L10. The ninth lens element L9 and the tenth lens elementL10 are cemented with each other with an adhesive layer in between.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex eleventh lens element L11; a positive meniscustwelfth lens element L12 with the convex surface facing the image side;a bi-concave thirteenth lens element L13; and a bi-convex fourteenthlens element L14. The twelfth lens element L12 and the thirteenth lenselement L13 are cemented with each other with an adhesive layer inbetween. The two surfaces of the eleventh lens element L11 are aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase, and the intervalbetween the fourth lens unit G4 and the fifth lens unit G5 shoulddecrease. The aperture diaphragm A moves to the object side togetherwith the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Further, for the purpose of compensation of image blur caused byvibration applied to the entire system, the fourth lens unit G4 moves ina direction perpendicular to the optical axis.

Embodiment 6

The zoom lens system according to Embodiment 6, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a fourth lens unit G4having negative optical power, and a fifth lens unit G5 having positiveoptical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; and a positive meniscus sixth lens element L6 with the convexsurface facing the object side. The object side surface of the fifthlens element L5 is aspheric.

The third lens unit G3 is composed of a bi-convex seventh lens elementL7. The two surfaces of the seventh lens element L7 are aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises: a positive meniscus eighth lens element L8 with theconvex surface facing the object side; and a negative meniscus ninthlens element L9 with the convex surface facing the object side. Theeighth lens element L8 and the ninth lens element L9 are cemented witheach other.

The fifth lens unit G5, in order from the object side to the image side,comprises a bi-convex tenth lens element L10, a bi-concave eleventh lenselement L11, and a bi-convex twelfth lens element L12. The object sidesurface of the eleventh lens element L11 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase and then decrease,and the interval between the fourth lens unit G4 and the fifth lens unitG5 should decrease. The aperture diaphragm A moves to the object sidetogether with the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Embodiment 7

The zoom lens system according to Embodiment 7, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a fourth lens unit G4having negative optical power, and a fifth lens unit G5 having positiveoptical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; and a positive meniscus sixth lens element L6 with the convexsurface facing the object side.

The third lens unit G3 is composed of a bi-convex seventh lens elementL7. The two surfaces of the seventh lens element L7 are aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises a bi-convex eighth lens element L8 and a bi-concaveninth lens element L9. The eighth lens element L8 and the ninth lenselement L9 are cemented with each other. The object side surface of theeighth lens element L8 is aspheric.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex tenth lens element L10; a bi-concave eleventhlens element L11; a bi-convex twelfth lens element L12; and aplaner-concave thirteenth lens element L13 with the concave surfacefacing the object side. The twelfth lens element L12 and the thirteenthlens element L13 are cemented with each other. The object side surfaceof the eleventh lens element L11 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase, and the intervalbetween the fourth lens unit G4 and the fifth lens unit G5 shoulddecrease. The aperture diaphragm A moves to the object side togetherwith the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Embodiment 8

The zoom lens system according to Embodiment 8, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a fourth lens unit G4having negative optical power, and a fifth lens unit G5 having positiveoptical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other with an adhesive layer in between.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a bi-convex sixth lens element L6; and a negative meniscus seventhlens element L7 with the convex surface facing the image side. The fifthlens element L5 and the sixth lens element L6 are cemented with eachother with an adhesive layer in between. The object side surface of theseventh lens element L7 is aspheric.

The third lens unit G3 is composed of a bi-convex eighth lens elementL8. The image side surface of the eighth lens element L8 is aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises: a positive meniscus ninth lens element L9 with theconvex surface facing the object side; and a negative meniscus tenthlens element L10 with the convex surface facing the object side. Theninth lens element L9 and the tenth lens element L10 are cemented witheach other with an adhesive layer in between.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex eleventh lens element L11; a negative meniscustwelfth lens element L12 with the convex surface facing the object side;a bi-convex thirteenth lens element L13; a negative meniscus fourteenthlens element L14 with the convex surface facing the image side; and abi-convex fifteenth lens element L15. The thirteenth lens element L13and the fourteenth lens element L14 are cemented with each other with anadhesive layer in between. The object side surface of the eleventh lenselement L11 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase, and the intervalbetween the fourth lens unit G4 and the fifth lens unit G5 shoulddecrease. The aperture diaphragm A moves to the object side togetherwith the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Embodiment 9

The zoom lens system according to Embodiment 9, in order from the objectside to the image side, comprises a first lens unit G1 having positiveoptical power, a second lens unit G2 having negative optical power, athird lens unit G3 having positive optical power, a fourth lens unit G4having negative optical power, and a fifth lens unit G5 having positiveoptical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other with an adhesive layer in between.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a bi-convex sixth lens element L6; and a negative meniscus seventhlens element L7 with the convex surface facing the image side. The fifthlens element L5 and the sixth lens element L6 are cemented with eachother with an adhesive layer in between. The object side surface of theseventh lens element L7 is aspheric.

The third lens unit G3 is composed of a bi-convex eighth lens elementL8. The image side surface of the eighth lens element L8 is aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises: a positive meniscus ninth lens element L9 with theconvex surface facing the object side; and a negative meniscus tenthlens element L10 with the convex surface facing the object side. Theninth lens element L9 and the tenth lens element L10 are cemented witheach other with an adhesive layer in between.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex eleventh lens element L11; a negative meniscustwelfth lens element L12 with the convex surface facing the object side;a bi-convex thirteenth lens element L13; a negative meniscus fourteenthlens element L14 with the convex surface facing the image side; and abi-convex fifteenth lens element L15. The thirteenth lens element L13and the fourteenth lens element L14 are cemented with each other with anadhesive layer in between. The object side surface of the eleventh lenselement L11 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should decrease and then increase,and the interval between the fourth lens unit G4 and the fifth lens unitG5 should decrease and then increase. The aperture diaphragm A moves tothe object side together with the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Embodiment 10

The zoom lens system according to Embodiment 10, in order from theobject side to the image side, comprises a first lens unit G1 havingpositive optical power, a second lens unit G2 having negative opticalpower, a third lens unit G3 having positive optical power, a fourth lensunit G4 having positive optical power, and a fifth lens unit G5 havingpositive optical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a bi-convex second lens element L2; anda positive meniscus third lens element L3 with the convex surface facingthe object side. The first lens element L1 and the second lens elementL2 are cemented with each other with an adhesive layer in between.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; a bi-convex sixth lens element L6; and a negative meniscus seventhlens element L7 with the convex surface facing the image side.

The third lens unit G3 is composed of a bi-convex eighth lens elementL8. The two surfaces of the eighth lens element L8 are aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises: a negative meniscus ninth lens element L9 with theconvex surface facing the object side; and a positive meniscus tenthlens element L10 with the convex surface facing the object side. Theninth lens element L9 and the tenth lens element L10 are cemented witheach other with an adhesive layer in between.

The fifth lens unit G5, in order from the object side to the image side,comprises: a bi-convex eleventh lens element L11; a negative meniscustwelfth lens element L12 with the convex surface facing the object side;a bi-convex thirteenth lens element L13; a bi-concave fourteenth lenselement L14; and a bi-convex fifteenth lens element L15. The twelfthlens element L12, the thirteenth lens element L13 and the fourteenthlens element L14 are cemented with each other, each with an adhesivelayer in between. The object side surface of the eleventh lens elementL11 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase, and the intervalbetween the fourth lens unit G4 and the fifth lens unit G5 shoulddecrease. The aperture diaphragm A moves to the object side togetherwith the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

Embodiment 11

The zoom lens system according to Embodiment 11, in order from theobject side to the image side, comprises a first lens unit G1 havingpositive optical power, a second lens unit G2 having negative opticalpower, a third lens unit G3 having positive optical power, a fourth lensunit G4 having negative optical power, and a fifth lens unit G5 havingpositive optical power.

The first lens unit G1, in order from the object side to the image side,comprises: a negative meniscus first lens element L1 with the convexsurface facing the object side; a positive meniscus second lens elementL2 with the convex surface facing the object side; and a positivemeniscus third lens element L3 with the convex surface facing the objectside. The first lens element L1 and the second lens element L2 arecemented with each other.

The second lens unit G2, in order from the object side to the imageside, comprises: a negative meniscus fourth lens element L4 with theconvex surface facing the object side; a bi-concave fifth lens elementL5; and a positive meniscus sixth lens element L6 with the convexsurface facing the object side. The object side surface of the fifthlens element L5 is aspheric.

The third lens unit G3 is composed of a bi-convex seventh lens elementL7. The two surfaces of the seventh lens element L7 are aspheric.

The fourth lens unit G4, in order from the object side to the imageside, comprises a bi-convex eighth lens element L8 and a bi-concaveninth lens element L9. The eighth lens element L8 and the ninth lenselement L9 are cemented with each other.

The fifth lens unit G5, in order from the object side to the image side,comprises a bi-convex tenth lens element L10, a bi-concave eleventh lenselement L11, and a bi-convex twelfth lens element L12. The object sidesurface of the eleventh lens element L11 is aspheric.

In zooming from a wide-angle limit to a telephoto limit, the first lensunit G1 to the fifth lens unit G5 individually move to the object side.More specifically, in zooming from a wide-angle limit to a telephotolimit, the individual lens units move along the optical axis such thatthe interval between the first lens unit G1 and the second lens unit G2should increase, the interval between the second lens unit G2 and thethird lens unit G3 should decrease, the interval between the third lensunit G3 and the fourth lens unit G4 should increase and then decrease,and the interval between the fourth lens unit G4 and the fifth lens unitG5 should decrease. The aperture diaphragm A moves to the object sidetogether with the fourth lens unit G4.

Further, at the time of focusing from an infinity in-focus condition toa close-point in-focus condition, the third lens unit G3 moves to theimage side along the optical axis.

The zoom lens system according to each of the above-mentionedembodiments includes, in order from an object side to an image side: afirst lens unit having positive optical power; a second lens unit havingnegative optical power; a third lens unit having positive optical power;and an aperture diaphragm. At the time of zooming, each zoom lens systemmoves the first to third lens units so that intervals between these lensunits vary. Further, at the time of focusing from an infinity in-focuscondition to a close-point object in-focus condition, each zoom lenssystem moves the third lens unit to the object side. This arrangement ofthe focusing lens unit reduces the image magnification change generatedat the time of focusing.

The following description is given for conditions to be satisfied by thezoom lens system according to each embodiment. Here, in the zoom lenssystem according to each embodiment, a plurality of conditions to besatisfied are set forth. Thus, a configuration of a zoom lens systemthat satisfies as many applicable conditions as possible is mostpreferable. However, when an individual condition is satisfied, a zoomlens system having the corresponding effect can be obtained.

It is preferable that the zoom lens system according to each embodimentsatisfies the following condition.1.2<|f _(F) /f _(W)|<6.0  (1)

(here, f_(T)/f_(W)>3.0)

where,

f_(F) is a focal length of the focusing lens unit,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (1) sets forth the focal length of the focusing lens unit.When the value exceeds the upper limit of the condition (1), the focallength of the focusing lens unit becomes excessively great, and hencethe amount of movement at the time of focusing increases. This preventsrealization of a compact zoom lens system. In contrast, when the valuegoes below the lower limit of the condition (1), The focal length of thefocusing lens unit becomes excessively small. Thus, aberrationfluctuation at the time of focusing becomes excessively large.Accordingly, aberration cannot be compensated by other lens units.

It is preferable that the zoom lens system according to each embodimentsatisfies the following condition.0.10<|f _(F) /f _(T)|<1.8  (2)

(here, f_(T)/f_(W)>3.0)

where,

f_(F) is a focal length of the focusing lens unit,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (2) sets forth the focal length of the focusing lens unit.When the value exceeds the upper limit of the condition (2), the focallength of the focusing lens unit becomes excessively great, and hencethe amount of movement at the time of focusing increases. This preventsrealization of a compact zoom lens system. In contrast, when the valuegoes below the lower limit of the condition (2), the focal length of thefocusing lens unit becomes excessively small. Thus, aberrationfluctuation at the time of focusing becomes excessively large. Further,error sensitivity in the focusing lens unit becomes high. This causesdifficulty in assembling and adjustment.

It is preferable that the zoom lens system according to each embodimentsatisfies the following condition.1.00<|f _(F) /f _(NW)|<5.00  (3)

(here, f_(T)/f_(W)>3.0)

where,

f_(F) is a focal length of the focusing lens unit,

f_(NW) is a composite focal length of the focusing lens unit and thenegative lens unit in an infinity in-focus condition at a wide-anglelimit when the focusing lens unit has negative optical power, or thefocal length of the negative lens unit when the focusing lens unit haspositive optical power,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (3) sets forth the ratio between the focal length of thefocusing lens unit and the focal length of the negative lens unit. Whenthe value exceeds the upper limit of the condition (3), the focal lengthof the focusing lens unit becomes excessively great, and hence theamount of movement at the time of focusing increases. This preventsrealization of a compact zoom lens system. In contrast, when the valuegoes below the lower limit of the condition (3), aberration fluctuationgenerated at the time of zooming cannot be compensated by the subsequentlens units. Further, the image magnification change generated inassociation with the movement of the focusing lens unit becomesexcessively large. Thus, this situation is unpreferable.

Among the zoom lens systems according to the individual embodiments,when the negative lens unit is arranged on the image side relative tothe lens unit having positive optical power with the interval in betweenthat varies at the time of zooming, it is preferable that the zoom lenssystem satisfies the following condition.1.20<β_(NT)/β_(NW)<4.50  (4)

(here, f_(T)/f_(W)>3.0)

where,

β_(NT) is a composite focal length of the focusing lens unit and thenegative lens unit in an infinity in-focus condition at a telephotolimit when the focusing lens unit has negative optical power, or alateral magnification of the negative lens unit at a telephoto limit inan infinity in-focus condition when the focusing lens unit has positiveoptical power,

β_(NW) is a composite focal length of the focusing lens unit and thenegative lens unit in an infinity in-focus condition at a wide-anglelimit when the focusing lens unit has negative optical power, or alateral magnification of the negative lens unit at a wide-angle limit inan infinity in-focus condition when the focusing lens unit has positiveoptical power,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (4) sets forth the magnification change in the negativelens unit, and substantially indicates the fraction of contribution tozooming. When the value goes outside the range of the condition (4),this situation causes difficulty in zooming itself. Further, aberrationfluctuation generated at the time of zooming becomes excessively large,and hence cannot be compensated by other lens units.

Among the zoom lens systems according to the individual embodiments,when the negative lens unit is arranged on the image side relative tothe lens unit having positive optical power with the interval in betweenthat varies at the time of zooming, it is preferable that the zoom lenssystem satisfies the following condition.0.01<D _(F) /ΣD<0.10  (5)

where,

D_(F) is an axial thickness of the focusing lens unit, and

ΣD is a total of axial thicknesses of the lens elements in the entiresystem.

The condition (5) sets forth the axial thickness of the focusing lensunit. When the value exceeds the upper limit of the condition (5), thefocusing lens unit becomes excessively large. This causes difficulty infocusing such as wobbling suitable for video image taking. In contrast,when the value goes below the lower limit of the condition (5), thissituation causes difficulty in ensuring a focal length required forfocusing. That is, the amount of movement at the time of focusingbecomes excessively large, and hence this situation is unpreferable.

Among the zoom lens systems according to the individual embodiments,when the negative lens unit is arranged on the image side relative tothe lens unit having positive optical power with the interval in betweenthat varies at the time of zooming, it is preferable that the zoom lenssystem satisfies the following condition.3.20<|f ₁ /f _(NW)|<8.50  (6)

(here, f_(T)/f_(W)>3.0)

where,

f₁ is a focal length of the positive lens unit arranged on the objectside of the focusing lens unit,

f_(NW) is a composite focal length of the focusing lens unit and thenegative lens unit in an infinity in-focus condition at a wide-anglelimit when the focusing lens unit has negative optical power, or thefocal length of the negative lens unit when the focusing lens unit haspositive optical power,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (6) sets forth the focal length of the positive lens unitarranged on the object side of the focusing lens unit. When the valueexceeds the upper limit of the condition (6), aberration fluctuationgenerated at the time of zooming becomes excessively large. Further,difficulty arises in compensating off-axial aberration, especially,distortion. Thus, this situation is unpreferable. In contrast, when thevalue goes below the lower limit of the condition (6), aberrationfluctuation generated at the time of zooming becomes excessively large.Further, degradation is caused in the performance at the time offocusing on a close object, and hence this situation is unpreferable.

Among the zoom lens systems according to the individual embodiments, ina case that the negative lens unit is arranged on the image siderelative to the lens unit having positive optical power with theinterval in between that varies at the time of zooming and that thefocusing lens unit has positive optical power, it is preferable that thezoom lens system satisfies the following condition.0.15<D _(FWA) /f _(W)<0.30  (14)

(here, f_(T)/f_(W)>3.0)

where,

D_(FWA) is an axial interval from the vertex of a surface on the mostimage side of the focusing lens unit to the aperture diaphragm,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (14) sets forth the axial interval from the focusing lensunit to the aperture diaphragm in a case that the focusing lens unit hasnegative optical power. When the value exceeds the upper limit of thecondition (14), the axial interval between the focusing lens unit andthe aperture diaphragm becomes excessively great, and hence the focallength of the focusing lens unit increases relatively. This causesdifficulty in realizing a compact zoom lens system. Further, when thevalue exceeds the upper limit of the condition (14), difficulty arisesin compensating aberration, especially, spherical aberrationfluctuation, generated at the time of focusing. In contrast, when thevalue goes below the lower limit of the condition (14), the axialinterval between the focusing lens unit and the aperture diaphragmbecomes excessively small. This causes difficulty in compensatingdistortion especially at a wide-angle limit, and hence this situation isunpreferable.

Among the zoom lens systems according to the individual embodiments, ina case that the negative lens unit is arranged on the image siderelative to the lens unit having positive optical power with theinterval in between that varies at the time of zooming and that thefocusing lens unit has positive optical power, it is preferable that thezoom lens system satisfies the following condition.0.50<(D _(F) /f _(W))*(f _(T) /f _(W))<1.50  (15)

(here, f_(T)/f_(W)>3.0)

where,

D_(F) is an axial thickness of the focusing lens unit,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (15) sets forth the axial thickness of the focusing lensunit. When the value exceeds the upper limit of the condition (15), theaxial thickness of the focusing lens unit becomes excessively great, andhence the weight of the focusing lens unit increases. Thus, thissituation is unpreferable. In contrast, when the value goes below thelower limit of the condition (15), the axial thickness of the focusinglens unit becomes excessively small. This causes difficulty inmanufacturing.

Among the zoom lens systems according to the individual embodiments, ina case that the negative lens unit is arranged on the image siderelative to the lens unit having positive optical power with theinterval in between that varies at the time of zooming and that thefocusing lens unit has positive optical power, it is preferable that thezoom lens system satisfies the following condition.0.02|D _(F) /f _(F)|<0.15  (16)

(here, f_(T)/f_(W)>3.0)

where,

D_(F) is an axial thickness of the focusing lens unit,

f_(F) is a focal length of the focusing lens unit,

f_(T) is a focal length of the entire system at a telephoto limit, and

f_(W) is focal length of the entire system at a wide-angle limit.

The condition (16) relates to the focal length of the focusing lensunit. When the value exceeds the upper limit of the condition (16), thefocal length of the focusing lens unit becomes excessively small. Thiscauses difficulty in compensating aberration fluctuation at the time offocusing. In contrast, when the value goes below the lower limit of thecondition (16), the focal length of the focusing lens unit becomesexcessively great. Thus, the amount of movement at the time of focusing,especially at the time of wobbling, becomes excessively large. Hence,this situation is unpreferable.

Among the zoom lens systems according to the individual embodiments, ina case that the negative lens unit is arranged on the image siderelative to the lens unit having positive optical power with theinterval in between that varies at the time of zooming and that thefocusing lens unit has positive optical power, it is preferable that thezoom lens system satisfies the following condition.3.00<|f ₁ /f ₂|<8.00  (17)

where,

f₁ is a focal length of the positive lens unit, and

f₂ is a focal length of the negative lens unit.

The condition (17) sets forth the focal length ratio between thepositive lens unit and the negative lens unit. When the value exceedsthe upper limit of the condition (17), this indicates that the focallength of the positive lens unit is excessively great. This causesdifficulty in compensating distortion. In contrast, when the value goesbelow the lower limit of the condition (17), this indicates that thefocal length of the negative lens unit is excessively great. Thus, theamount of movement of the negative lens unit at the time of zoomingbecomes excessively large, and hence this situation is unpreferable.

Among the zoom lens systems according to the individual embodiments, ina case that the negative lens unit is arranged on the image siderelative to the lens unit having positive optical power with theinterval in between that varies at the time of zooming and that thefocusing lens unit has positive optical power, it is preferable that thezoom lens system satisfies the following condition.0.20<|f ₂ /f _(F)|<0.80  (18)

where,

f₂ is a focal length of the negative lens unit, and

f_(F) is a focal length of the focusing lens unit.

The condition (18) sets forth the focal length ratio between thefocusing lens unit and the negative lens unit. When the value exceedsthe upper limit of the condition (18), this indicates that the focallength of the focusing lens unit is excessively small. Thus, the imagemagnification change at the time of focusing becomes excessively large,and hence this situation is unpreferable. In contrast, when the valuegoes below the lower limit of the condition (18), this indicates thatthe focal length of the negative lens unit is excessively small. Thiscauses an increase in aberration fluctuation at the time of zooming, andhence causes difficulty in compensation by other lens units.

Among the zoom lens systems according to the individual embodiments, ina case that the negative lens unit is arranged on the image siderelative to the lens unit having positive optical power with theinterval in between that varies at the time of zooming and that thefocusing lens unit has positive optical power, it is preferable that thezoom lens system satisfies the following condition.1.50|f ₁ /f _(F)|<4.00  (19)

where,

f₁ is a focal length of the lens unit having positive optical power, and

f_(F) is a focal length of the focusing lens unit.

The condition (19) sets forth the focal length ratio between thefocusing lens unit and the positive lens unit. When the value exceedsthe upper limit of the condition (19), this indicates that the focallength of the focusing lens unit is excessively small. Thus, the imagemagnification change at the time of focusing becomes excessively large,and hence this situation is unpreferable. In contrast, when the valuegoes below the lower limit of the condition (19), this indicates thatthe focal length of the positive lens unit is excessively small. Thiscauses an increase in aberration fluctuation at the time of zooming, andhence causes difficulty in compensation by other lens units.

Here, the individual lens units constituting each embodiment arecomposed exclusively of refractive type lens elements that deflectincident light by refraction (that is, lens elements of a type in whichdeflection is achieved at the interface between media each having adistinct refractive index). However, the present invention is notlimited to this construction. For example, the lens units may employdiffractive type lens elements that deflect the incident light bydiffraction; refractive-diffractive hybrid type lens elements thatdeflect the incident light by a combination of diffraction andrefraction; or gradient index type lens elements that deflect theincident light by distribution of refractive index in the medium.

Embodiment 12

FIG. 39 is a block diagram of a camera system according to Embodiment12. The camera system according to Embodiment 12 includes a camera body100 and an interchangeable lens apparatus 200.

The camera body 100 includes a camera controller 101, an image sensor102, a shutter unit 103, an image display controller 104, an imagesensor control section 105, a contrast detection section 106, a shuttercontrol section 107, an image recording control section 108, a display110, a release button 111, a memory 112, a power supply 113 and a cameramount 114.

The camera controller 101 is an arithmetic operation unit forcontrolling the entire camera system. The camera controller 101 iselectrically connected to the image display controller 104, the imagesensor control section 105, the contrast detection section 106, theshutter control section 107, the image recording control section 108,the memory 112 and the camera mount 114, and can exchange signals withthese sections. Further, the camera controller 101 is electricallyconnected to the release button 111, and receives a signal generated atthe time of operation of the release button 111. Moreover, the cameracontroller 101 is connected to the power supply 113.

The image sensor 102 is composed, for example, of a CMOS sensor. Theimage sensor 102 converts an optical image incident on the lightreceiving plane into image data, and then outputs the image data. Theimage sensor 102 is driven in accordance with a driving signal from theimage sensor control section 105. In response to a control signal fromthe camera controller 101, the image sensor control section 105 outputsa driving signal for driving the image sensor 102, and then outputs tothe camera controller 101 the image data outputted from the image sensor102. In response to a control signal from the camera controller 101, thecontrast detection section 106 calculates and detects the contrast ofthe image data outputted from the image sensor 102, and then outputs theresult to the camera controller 101.

The shutter unit 103 includes a shutter plate for shutting off theoptical path for the image light to be incident on the image sensor 102.The shutter unit 103 is driven in accordance with a driving signal fromthe shutter control section 107. In response to a control signal fromthe camera controller 101, the shutter control section 107 controls theopening or closing timing for the shutter plate of the shutter unit 103.

The display 110 is composed, for example, of a liquid crystal displayunit. The display 110 is driven in accordance with a driving signal fromthe image display controller 104 so as to display an image on thedisplay surface. In response to a control signal from the cameracontroller 101, the image display controller 104 outputs image data tobe displayed on the display 110 and a driving signal for driving thedisplay 110.

In response to a control signal from the camera controller 101, theimage recording control section 108 outputs image data to a memory card109 connected in an attachable and removable manner.

The camera mount 114 mechanically connects the camera body 100 to theinterchangeable lens apparatus 200 described later. Further, the cameramount 114 serves also as an interface for electrically connecting thecamera body 100 to the interchangeable lens apparatus 200 describedlater.

The interchangeable lens apparatus 200 includes a lens controller 201,an image blur control section 202, a diaphragm control section 203, afocus control section 204, a zoom control section 205, a memory 206, ablur detection section 207, a diaphragm unit 208, a zoom lens system 209(a zoom lens unit 209 a, a focusing lens unit 209 b and an image blurcompensation lens unit 209 c), and a lens mount 210.

The lens controller 201 is an arithmetic operation unit for controllingthe entirety of the interchangeable lens apparatus 200, and is connectedthrough the lens mount 210 and the camera mount 114 to the cameracontroller 101 in the camera body described above. The lens controller201 is electrically connected to the image blur control section 202, thediaphragm control section 203, the focus control section 204, the zoomcontrol section 205, the memory 206 and the blur detection section 207,and can exchange signals with these sections.

The zoom lens system 209 is a zoom lens system according to Embodiment 1described above. The zoom lens system 209 includes a zoom lens unit 209a, a focusing lens unit 209 b, and an image blur compensation lens unit209 c. Here, the classification of the zoom lens unit 209 a, thefocusing lens unit 209 b and the image blur compensation lens unit 209 cis merely conceptual and adopted for simplicity of description. Thus,this classification does not exactly describe the actual construction ofthe actual zoom lens system. In the zoom lens system 209, zooming isachieved when the zoom lens unit 209 a moves in a direction along theoptical axis. In the zoom lens system 209, focusing is achieved when thefocusing lens unit 209 b moves in a direction along the optical axis.Further, in the zoom lens system 209, image blur compensation isachieved when the image blur compensation lens unit 209 c moves in adirection perpendicular to the optical axis.

In response to a control signal from the lens controller 201, the imageblur control section 202 detects and outputs the present position of theimage blur compensation lens unit 209 c. Further, the image blur controlsection 202 outputs a driving signal for driving the image blurcompensation lens unit 209 c, so as to drive the image blur compensationlens unit 209 c in a direction perpendicular to the optical axis.

In response to a control signal from the lens controller 201, thediaphragm control section 203 detects and outputs the present positionof the diaphragm unit 208. Further, the diaphragm control section 203outputs a driving signal for driving the diaphragm blades provided inthe diaphragm unit 208, and thereby opens or closes the diaphragm so asto change the F-number of the optical system.

In response to a control signal from the lens controller 201, the focuscontrol section 204 detects and outputs the present position of thefocusing lens unit 209 b. Further, the focus control section 204 outputsa driving signal for driving focusing group 209 b, so as to drive thefocusing lens unit 209 b in a direction along the optical axis.

In response to a control signal from the lens controller 201, the zoomcontrol section 205 detects and outputs the present position of the zoomlens unit 209 a. Further, the zoom control section 205 outputs a drivingsignal for driving the zoom lens unit 209 a, so as to drive the zoomlens unit 209 a in a direction along the optical axis.

In the above-mentioned configuration, when the release button 111 ispressed half, the camera controller 101 executes a routine ofauto-focusing. First, the camera controller 101 communicates with thelens controller 201 via the camera mount 114 and the lens mount 210, soas to detect the state of the zoom lens unit 209 a, the focusing lensunit 209 b, the image blur compensation lens unit 209 c and thediaphragm unit 208.

Then, the camera controller 101 communicates with the lens controller201 via the camera mount 114 and the lens mount 210, so as to output tothe lens controller 201 a control signal for driving and wobbling thefocusing lens unit 209 b. In accordance with the control signal, thelens controller 201 controls the focus control section 204 so as todrive and wobble the focusing lens unit 209 b. At the same time, thecamera controller 101 communicates with the lens controller 201 via thecamera mount 114 and the lens mount 210, so as to output a controlsignal for instructing the lens controller 201 to adjust the aperturevalue into a predetermined value. In accordance with the control signal,the lens controller 201 controls the diaphragm control section 203 so asto drive the diaphragm blades of the diaphragm unit 208 incorrespondence to the predetermined F-number.

On the other hand, the camera controller 101 outputs a control signal tothe image sensor control section 105 and the contrast detection section106. The image sensor control section 105 and the contrast detectionsection 106 individually acquire an output from the image sensor 102 ina manner corresponding to the sampling frequency of the wobbling driveof the focusing lens unit 209 b. In accordance with the control signalfrom the camera controller 101, the image sensor control section 105transmits image data corresponding to the optical image to the cameracontroller 101. The camera controller 101 performs predetermined imageprocessing onto the image data, and then transmits the result to theimage display controller 104. The image display controller 104 displaysthe image data in the form of a visible image onto the display 110.

Further, the contrast detection section 106 calculates the contrastvalue of the image data in association with wobbling, and then transmitsthe result to the camera controller 101. On the basis of the detectionresult from the contrast detection section 106, the camera controller101 determines the direction of focusing movement and the amount ofmovement for the focusing lens unit, and then transmits the informationthereof to the lens controller 201. The lens controller 201 outputs acontrol signal to the focus control section 204 so as to move thefocusing lens unit 209 b. In accordance with the control signal from thelens controller 201, the focus control section 204 drives the focusinglens unit 209 b.

When auto-focusing is to be performed in a live view state, theabove-mentioned operation is repeated. When auto-focusing is to beperformed in a live view state, wobbling of the focusing lens unit 209 bis performed continuously. At that time, the zoom lens system accordingto each embodiment has merely a small image magnification change inassociation with wobbling, and has a light weight. Thus, an imaging lenssystem suitable for the above-mentioned system is obtained.

Embodiment 12 given above has been described for a case that the zoomlens system according to Embodiment 1 is employed. However, obviously, azoom lens system according to another embodiment may be employed. Here,among the zoom lens systems according to the embodiments, when a zoomlens system that does not include the image blur compensation lens unit209 c is employed, the configuration of the image blur control section202 and the like is omitted.

EXAMPLES

Numerical examples are described below in which the zoom lens systemsaccording to Embodiments 1 to 11 are implemented. As described later,Numerical Examples 1 to 11 correspond to Embodiments 1 to 11,respectively. In the numerical examples, the units of the length in thetables are all “mm”, while the units of the view angle are all “°”.Moreover, in the numerical examples, r is the radius of curvature, d isthe axial distance, nd is the refractive index to the d-line, and vd isthe Abbe number to the d-line. In the numerical examples, the surfacesmarked with * are aspheric surfaces, and the aspheric surfaceconfiguration is defined by the following expression.

$Z = {\frac{h^{2}/r}{1 + \sqrt{1 - {\left( {1 + \kappa} \right)\left( {h/r} \right)^{2}}}} + {\sum{A_{n}h^{n}}}}$

Here, the symbols in the formula indicate the following quantities.

Z is the distance from a point on an aspheric surface at a height hrelative to the optical axis to a tangential plane at the vertex of theaspheric surface,

h is the height relative to the optical axis,

r is the radius of curvature at the top,

k is the conic constant, and

An is the n-th order aspherical coefficient.

FIGS. 2, 6, 10, 14, 18, 22, 25, 28, 31, 34 and 37 are longitudinalaberration diagrams of an infinity in-focus condition of the zoom lenssystems according to Numerical Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10and 11, respectively.

FIGS. 3, 7, 11, 15, 19, 23, 26, 29, 32, 35 and 38 are longitudinalaberration diagrams of a close-point in-focus condition of the zoom lenssystems according to Numerical Examples 1, 2, 3, 4, 5, 6, 7, 8, 9, 10and 11, respectively.

In each longitudinal aberration diagram, part (a) shows the aberrationat a wide-angle limit, part (b) shows the aberration at a middleposition, and part (c) shows the aberration at a telephoto limit. Eachlongitudinal aberration diagram, in order from the left-hand side, showsthe spherical aberration (SA (mm)), the astigmatism (AST (mm)) and thedistortion (DIS (%)). In each spherical aberration diagram, the verticalaxis indicates the F-number (in each Fig., indicated as F), and thesolid line, the short dash line and the long dash line indicate thecharacteristics to the d-line, the F-line and the C-line, respectively.In each astigmatism diagram, the vertical axis indicates the imageheight (in each Fig., indicated as H), and the solid line and the dashline indicate the characteristics to the sagittal image plane (in eachFig., indicated as “s”) and the meridional image plane (in each Fig.,indicated as “m”), respectively. In each distortion diagram, thevertical axis indicates the image height (in each Fig., indicated as H).

In each numerical example, as seen from the longitudinal aberrationdiagram of an infinity in-focus condition and the longitudinalaberration diagram of a close-point in-focus condition, also in aclose-point in-focus condition, each zoom lens system achievessatisfactory aberration performance similar to that in an infinityin-focus condition.

FIGS. 4, 8, 12, 16 and 20 are lateral aberration diagrams in a basicstate where image blur compensation is not performed and in an imageblur compensation state of a zoom lens system according to NumericalExamples 1, 2, 3, 4 and 5, respectively.

In each lateral aberration diagram, the aberration diagrams in the upperthree parts correspond to a basic state where image blur compensation isnot performed at a telephoto limit, while the aberration diagrams in thelower three parts correspond to an image blur compensation state wherethe entire second lens unit G2 moves by a predetermined amount in adirection perpendicular to the optical axis at a telephoto limit. Amongthe lateral aberration diagrams of a basic state, the upper part showsthe lateral aberration at an image point of 75% of the maximum imageheight, the middle part shows the lateral aberration at the axial imagepoint, and the lower part shows the lateral aberration at an image pointof −75% of the maximum image height. Among the lateral aberrationdiagrams of an image blur compensation state, the upper part shows thelateral aberration at an image point of 75% of the maximum image height,the middle part shows the lateral aberration at the axial image point,and the lower part shows the lateral aberration at an image point of−75% of the maximum image height. In each lateral aberration diagram,the horizontal axis indicates the distance from the principal ray on thepupil surface, and the solid line, the short dash line and the long dashline indicate the characteristics to the d-line, the F-line and theC-line, respectively. In each lateral aberration diagram, the meridionalimage plane is adopted as the plane containing the optical axis of thefirst lens unit G1.

Here, in the zoom lens system according to each numerical example, theamount (Y_(T)) of movement of the compensation lens unit in a directionperpendicular to the optical axis in an image blur compensation state ata telephoto limit is as follows.

TABLE 1 (amount of movement of compensation lens unit) Numerical ExampleY_(T) 1 0.400 2 0.500 3 0.500 4 0.200 5 0.050

As seen from the lateral aberration diagrams, in each zoom lens system,satisfactory symmetry is obtained in the lateral aberration at the axialimage point. Further, when the lateral aberration at the +75% imagepoint and the lateral aberration at the −75% image point are comparedwith each other in a basic state, all have a small degree of curvatureand almost the same inclination in the aberration curve. Thus,decentering coma aberration and decentering astigmatism are small. Thisindicates that satisfactory imaging performance is obtained even in animage blur compensation state. Further, when the image blur compensationangle of a zoom lens system is the same, the amount of paralleltranslation required for image blur compensation decreases withdecreasing focal length of the entire zoom lens system. Thus, atarbitrary zoom positions, satisfactory image blur compensation can beperformed without degrading the imaging characteristics.

Numerical Example 1

The zoom lens system of Numerical Example 1 corresponds to Embodiment 1shown in FIG. 1. Table 2 shows the surface data of the zoom lens systemof Numerical Example 1. Table 3 shows the aspherical data. Table 4 showsvarious data. Table 5 shows the zoom lens unit data.

TABLE 2 (surface data) Surface number r d nd vd Object surface ∞  180.00000 1.20000 1.84666 23.8  2 35.23940 4.60490 1.62299 58.1  3146.60500 0.10000  4 32.99430 4.17360 1.80420 46.5  5 121.46300 Variable 6* 56.16390 1.20000 1.85976 40.5  7 8.12330 4.35250  8 −21.456500.70000 1.88300 40.8  9 34.64830 0.71300 10 22.59170 2.59950 1.9228620.9 11 −28.93770 0.83860 12 −13.14350 0.80000 1.80420 46.5 13 −30.75660Variable 14 19.23570 0.70000 1.81183 28.8 15 10.73730 2.42280 1.6413956.0 16* −36.39360 Variable 17 (Aperture) ∞ 0.80000 18 14.06440 2.430701.63547 59.4 19 −37.47820 0.10000 20 48.44800 2.04680 1.51782 55.4 21−14.08110 0.80000 1.80429 46.4 22 13.50040 Variable 23 18.77840 3.505201.48749 70.4 24 −15.03170 0.09980 25* −38.22710 1.20000 1.68400 31.3 2624.64730 0.47430 27 48.87990 3.73520 1.56071 43.9 28 −10.22970 0.700001.80420 46.5 29 −35.25900 BF Image surface ∞

TABLE 3 (aspherical data) Surface No. Parameters 6 K = 0.00000E+00, A4 =3.77145E−05, A6 = −3.27660E−07, A8 = 4.20835E−09, A10 = −3.84294E−11,A12 = 1.53222E−13 16 K = 0.00000E+00, A4 = 3.61692E−05, A6 =−6.05514E−08, A8 = −1.68025E−09, A10 = 0.00000E+00, A12 = 0.00000E+00 25K = 0.00000E+00, A4 = −9.27327E−05, A6 = −7.61534E−07, A8 =−1.95775E−09, A10 = 2.58420E−10, A12 = −3.50474E−12

TABLE 4 (various data) Zooming ratio 4.77508 Wide Middle Telephoto Focallength 12.2510 26.7706 58.4997 F-number 3.60055 5.10050 5.70104 Viewangle 43.5988 21.8377 10.3518 Image height 11.0000 11.0000 11.0000Overall length of 75.1917 87.4143 107.7782 lens system BF 14.2328027.63772 41.54696 d5 0.8000 10.1196 20.3594 d13 11.2845 4.7436 1.2000d16 2.0562 2.3579 3.1478 d22 6.5213 2.2586 1.2271

TABLE 5 (zoom lens unit data) Unit Initial surface No. Focal length 1 155.88415 2 6 −8.05102 3 14 23.12958 4 17 169.26047 5 23 41.63152

Numerical Example 2

The zoom lens system of Numerical Example 2 corresponds to Embodiment 2shown in FIG. 5. Table 6 shows the surface data of the zoom lens systemof Numerical Example 2. Table 7 shows the aspherical data. Table 8 showsvarious data. Table 9 shows the zoom lens unit data.

TABLE 6 (surface data) Surface number r d nd vd Object surface ∞  179.85740 1.20000 1.84666 23.8  2 42.90190 0.01000 1.56732 42.8  342.90190 4.02100 1.62299 58.1  4 178.47990 0.15000  5 36.47630 4.214001.58913 61.3  6 156.48860 Variable  7 75.42430 0.70000 1.88300 40.8  88.63110 4.99200  9 −27.78580 0.60000 1.72916 54.7 10 22.16910 0.010001.56732 42.8 11 22.16910 1.32120 1.94595 18.0 12 64.47310 0.15000 13*25.20890 1.78380 1.68400 31.3 14 200.13630 Variable 15* 31.56710 1.920501.68863 52.8 16* −24.98200 Variable 17 (Aperture) ∞ 0.80000 18 8.863203.88860 1.51214 67.9 19 −34.59720 0.01000 1.56732 42.8 20 −34.597200.60000 1.83400 37.3 21 10.45970 1.02340 22 −171.29230 0.70000 1.8142737.6 23 85.40420 Variable 24* 25.85530 3.50930 1.60820 57.8 25*−12.17470 0.15160 26 −37.41050 2.11200 1.48746 70.3 27 −12.12240 0.010001.56732 42.8 28 −12.12240 0.70000 1.82087 33.5 29 −623.66470 4.14200 3059.92360 1.62660 1.84679 23.9 31 −573.64510 BF Image surface ∞

TABLE 7 (aspherical data) Surface No. Parameters 13 K = 7.76662E−01, A4= 3.17829E−05, A6 = −8.33555E−08, A8 = −1.21719E−09, A10 = 1.59898E−10,A12 = −2.09850E−12 15 K = 0.00000E+00, A4 = −6.99200E−06, A6 =1.81625E−06, A8 = −2.31634E−08, A10 = 1.64207E−09, A12 = 0.00000E+00 16K = 0.00000E+00, A4 = 2.92032E−05, A6 = 1.26564E−06, A8 = −1.15990E−08,A10 = 1.65715E−09, A12 = 0.00000E+00 24 K = −7.69668E−01, A4 =−3.70313E−05, A6 = 8.27040E−07, A8 = −5.36566E−08, A10 = 1.55393E−09,A12 = −9.43912E−12 25 K = 1.15274E+00, A4 = 1.22175E−04, A6 =3.94692E−06, A8 = −9.69229E−08, A10 = 1.83580E−09, A12 = 0.00000E+00

TABLE 8 (various data) Zooming ratio 4.69384 Wide Middle Telephoto Focallength 12.3601 26.7744 58.0164 F-number 3.49386 4.94748 5.78661 Viewangle 44.7403 22.1717 10.5263 Image height 11.0000 11.0000 11.0000Overall length of 77.2022 90.3080 111.1832 lens system BF 15.0192626.33363 38.54196 d6 0.4209 12.9271 26.4526 d14 13.7989 5.6781 1.3151d16 3.2098 3.4219 4.0175 d23 4.4073 1.6013 0.5100

TABLE 9 (zoom lens unit data) Unit Initial surface No. Focal length 1 169.86430 2 7 −10.08322 3 15 20.53559 4 17 −34.55578 5 24 21.26831

Numerical Example 3

The zoom lens system of Numerical Example 3 corresponds to Embodiment 3shown in FIG. 9. Table 10 shows the surface data of the zoom lens systemof Numerical Example 3. Table 11 shows the aspherical data. Table 12shows various data. Table 13 shows the zoom lens unit data.

TABLE 10 (surface data) Surface number r d nd vd Object surface ∞  180.00000 1.20000 1.84666 23.8  2 43.67470 0.01000 1.56732 42.8  343.67470 4.41580 1.62299 58.1  4 314.96890 0.15000  5 39.85940 3.999801.58913 61.3  6 199.87000 Variable  7 107.66530 0.70000 1.88300 40.8  88.91870 4.77870  9 −28.67460 0.60000 1.72916 54.7 10 18.55870 0.010001.56732 42.8 11 18.55870 1.38500 1.94595 18.0 12 44.73720 0.15000 13*22.50310 1.83090 1.68400 31.3 14 149.31330 Variable 15* 31.63230 1.914901.60671 57.4 16* −23.40760 Variable 17 (Aperture) ∞ 0.80000 18 10.426803.70590 1.49434 66.2 19 293.33330 0.01000 1.56732 42.8 20 293.333300.60000 1.82093 33.5 21 12.24480 2.86850 22 −60.34770 0.70000 1.8042046.5 23 ∞ Variable 24* 23.63400 3.89020 1.60600 57.5 25* −22.458300.15000 26 27.72330 3.99190 1.48749 70.4 27 −21.04610 0.01000 1.5673242.8 28 −21.04610 0.70000 1.82852 29.8 29 18.79900 3.53510 30 29.945102.53130 1.84666 23.8 31 −705.16990 BF Image surface ∞

TABLE 11 (aspherical data) Surface No. Parameters 13 K = 5.57201E+00, A4= −3.56370E−05, A6 = −3.74234E−07, A8 = −1.39332E−08, A10 = 3.28664E−10,A12 = −4.83633E−12 15 K = 0.00000E+00, A4 = 1.15577E−05, A6 =−5.20999E−07, A8 = 1.19760E−07, A10 = 1.70358E−10, A12 = 0.00000E+00 16K = 0.00000E+00, A4 = 4.94436E−05, A6 = −4.81411E−07, A8 = 1.04384E−07,A10 = 6.85884E−10, A12 = 0.00000E+00 24 K = 0.00000E+00, A4 =8.79077E−06, A6 = −1.74664E−06, A8 = 4.96314E−08, A10 = −8.19694E−10,A12 = 2.72586E−12 25 K = 2.19312E+00, A4 = 6.16469E−05, A6 =−8.57834E−07, A8 = 2.53752E−08, A10 = −3.86943E−10, A12 = 0.00000E+00

TABLE 12 (various data) Zooming ratio 4.70901 Wide Middle TelephotoFocal length 12.3606 26.8091 58.2061 F-number 3.59003 4.95559 5.65473View angle 44.6462 22.0536 10.4938 Image height 11.0000 11.0000 11.0000Overall length of 84.7185 97.6260 118.6772 lens system BF 14.9686627.74422 41.07506 d6 0.4179 12.1408 25.2691 d14 14.8605 6.0603 1.3629d16 2.9824 3.9321 4.3321 d23 6.8510 3.1106 2.0000

TABLE 13 (zoom lens unit data) Unit Initial surface No. Focal length 1 165.51468 2 7 −9.77604 3 15 22.46848 4 17 −46.31576 5 24 23.77370

Numerical Example 4

The zoom lens system of Numerical Example 4 corresponds to Embodiment 4shown in FIG. 13. Table 14 shows the surface data of the zoom lenssystem of Numerical Example 4. Table 15 shows the aspherical data. Table16 shows various data. Table 17 shows the zoom lens unit data.

TABLE 14 (surface data) Surface number r d nd vd Object surface ∞  180.00000 1.20000 1.84666 23.8  2 43.69660 0.01000 1.56732 42.8  343.69660 3.88150 1.62299 58.1  4 157.89800 0.10000  5 35.15840 4.435401.58913 61.3  6 154.58910 Variable  7 44.74720 0.70000 1.88300 40.8  88.75050 5.05830  9 −26.46620 0.60000 1.72916 54.7 10 14.41410 0.010001.56732 42.8 11 14.41410 1.55510 1.94595 18.0 12 25.71210 0.10000 13*14.48460 1.92570 1.68400 31.3 14 51.53140 Variable 15* 51.43310 1.630201.68863 52.8 16* −25.11770 Variable 17 (Aperture) ∞ 1.50000 18 9.833104.44230 1.60311 60.7 19 −33.30170 0.01000 1.56732 42.8 20 −33.301700.60000 1.80610 33.3 21 10.37750 Variable 22* 26.68240 3.10680 1.6082057.8 23* −15.69060 0.80680 24 −67.36380 2.76710 1.48749 70.4 25−11.15520 0.01000 1.56732 42.8 26 −11.15520 0.70000 1.80610 33.3 2734.70820 2.32680 28 53.61740 2.36440 1.84666 23.8 29 −45.70260 BF Imagesurface ∞

TABLE 15 (aspherical data) Surface No. Parameters 13 K = −1.08699E+00,A4 = 1.98621E−06, A6 = 6.17544E−07, A8 = −4.81601E−08, A10 =1.15961E−09, A12 = −1.05549E−11 15 K = 0.00000E+00, A4 = −1.41590E−05,A6 = 8.39493E−06, A8 = −2.60947E−07, A10 = 8.46868E−09, A12 =0.00000E+00 16 K = 0.00000E+00, A4 = 1.73948E−05, A6 = 7.29318E−06, A8 =−2.08987E−07, A10 = 7.67727E−09, A12 = 0.00000E+00 22 K = −1.89956E+00,A4 = −2.26837E−05, A6 = 4.15838E−07, A8 = −2.91604E−08, A10 =2.58289E−10, A12 = 7.19058E−12 23 K = 6.66600E−01, A4 = 1.65507E−05, A6= 2.46380E−06, A8 = −8.78790E−08, A10 = 1.26195E−09, A12 = 0.00000E+00

TABLE 16 (various data) Zooming ratio 4.69353 Wide Middle TelephotoFocal length 12.3602 26.7801 58.0130 F-number 3.52521 4.71488 5.78858View angle 44.6330 22.2493 10.5212 Image height 11.0000 11.0000 11.0000Overall length of 77.2191 89.5268 111.1808 lens system BF 14.9692227.09637 39.63498 d6 0.3994 11.8062 25.4291 d14 14.0462 5.7627 1.4326d16 2.5685 3.0755 3.6755 d21 5.3954 1.9456 1.1682

TABLE 17 (zoom lens unit data) Unit Initial surface No. Focal length 1 168.92235 2 7 −9.77303 3 15 24.72151 4 17 −148.93870 5 22 26.64608

Numerical Example 5

The zoom lens system of Numerical Example 5 corresponds to Embodiment 5shown in FIG. 17. Table 18 shows the surface data of the zoom lenssystem of Numerical Example 5. Table 19 shows the aspherical data. Table20 shows various data. Table 21 shows the zoom lens unit data.

TABLE 18 (surface data) Surface number r d nd vd Object surface ∞  180.00000 1.20000 1.84666 23.8  2 41.58340 3.90830 1.62299 58.1  3144.84920 0.10000  4 37.06610 3.92650 1.72916 54.7  5 141.90650 Variable 6 33.75870 0.70000 1.88300 40.8  7 8.46830 5.19850  8 −20.55630 0.600001.72916 54.7  9 13.22520 0.01000 1.56732 42.8 10 13.22520 1.470201.94595 18.0 11 21.73160 0.10000 12* 13.49080 1.94590 1.68400 31.3 1360.48790 Variable 14* 46.43790 1.57530 1.68863 52.8 15* −30.28080Variable 16 (Aperture) ∞ 1.50000 17 11.07990 4.93530 1.61730 50.7 18−19.35760 0.01000 1.56732 42.8 19 −19.35760 0.60000 1.80610 33.3 2012.27420 Variable 21* 15.17120 4.11750 1.60820 57.8 22* −15.689100.10000 23 −101.99330 3.81360 1.48749 70.4 24 −8.95160 0.01000 1.5673242.8 25 −8.95160 0.70000 1.80610 33.3 26 19.61820 2.72370 27 34.100002.87450 1.84666 23.8 28 −50.88280 BF Image surface ∞

TABLE 19 (aspherical data) Surface No. Parameters 12 K = −2.91122E−01,A4 = −4.87111E−05, A6 = 3.58272E−07, A8 = −3.98970E−08, A10 =8.17183E−10, A12 = −7.54821E−12 14 K = 0.00000E+00, A4 = 1.14498E−04, A6= −5.87437E−06, A8 = 5.18078E−07, A10 = −5.23207E−09, A12 = 0.00000E+0015 K = 0.00000E+00, A4 = 1.17386E−04, A6 = −4.48009E−06, A8 =4.23034E−07, A10 = −2.80694E−09, A12 = 0.00000E+00 21 K = −1.26649E−01,A4 = −4.33738E−05, A6 = 2.51212E−06, A8 = −1.02847E−07, A10 =2.39403E−09, A12 = −1.16446E−11 22 K = −4.78064E−01, A4 = 4.82511E−06,A6 = 2.51419E−06, A8 = −9.22663E−08, A10 = 1.63502E−09, A12 =0.00000E+00

TABLE 20 (various data) Zooming ratio 4.69375 Wide Middle TelephotoFocal length 12.3606 26.7881 58.0176 F-number 3.51495 4.68243 5.78475View angle 44.6324 22.1606 10.5327 Image height 11.0000 11.0000 11.0000Overall length of 77.2128 90.9389 111.1817 lens system BF 14.9680526.13646 39.06839 d5 0.2654 12.3490 24.4182 d13 12.2765 5.4088 1.3371d15 2.4720 3.1413 3.1493 d20 5.1115 1.7840 1.0894

TABLE 21 (zoom lens unit data) Unit Initial surface No. Focal length 1 164.47440 2 6 −9.11719 3 14 26.84137 4 16 −171.73160 5 21 23.31583

Numerical Example 6

The zoom lens system of Numerical Example 6 corresponds to Embodiment 6shown in FIG. 21. Table 22 shows the surface data of the zoom lenssystem of Numerical Example 6. Table 23 shows the aspherical data. Table24 shows various data. Table 25 shows the zoom lens unit data.

TABLE 22 (surface data) Surface number r d nd vd Object surface ∞  181.18370 1.20000 1.84666 23.8  2 47.92900 4.31140 1.62299 58.1  3270.76510 0.10000  4 55.46980 2.96000 1.80420 46.5  5 152.01960 Variable 6 35.00000 0.70000 1.90366 31.3  7 9.59050 6.10680  8* −18.760501.10000 1.68966 53.0  9 27.20680 0.20450 10 21.95800 2.10350 1.9459518.0 11 518.28290 Variable  12* 57.66300 1.55880 1.66547 55.2  13*−25.83970 Variable 14 ∞ 0.80000 (Aperture) 15 12.32080 4.50000 1.4874970.4 16 53.34470 2.94110 1.84666 23.8 17 14.90930 Variable 18 19.511705.00000 1.48749 70.4 19 −23.84230 0.96840  20* −34.70410 1.10000 1.8466623.8 21 23.21970 2.19410 22 27.08650 4.43980 1.75520 27.5 23 −40.27110BF Image surface ∞

TABLE 23 (aspherical data) Surface No. Parameters 8 K = 0.00000E+00, A4= 1.14451E−05, A6 = −9.67896E−08, A8 = −3.12143E−09, A10 = 0.00000E+00,A12 = 0.00000E+00 12 K = 0.00000E+00, A4 = −8.09473E−05, A6 =2.35817E−06, A8 = −5.50379E−08, A10 = 0.00000E+00, A12 = 0.00000E+00 13K = 0.00000E+00, A4 = −5.63697E−05, A6 = 2.26951E−06, A8 = −5.35582E−08,A10 = 0.00000E+00, A12 = 0.00000E+00 20 K = 0.00000E+00, A4 =−6.16776E−05, A6 = −5.26771E−07, A8 = −8.63502E−09, A10 = 3.94452E−10,A12 = −3.94169E−12

TABLE 24 (various data) Zooming ratio 4.70495 Wide Middle TelephotoFocal length 12.3700 26.8312 58.2002 F-number 3.56995 4.89113 5.78961View angle 43.1080 21.9037 10.4919 Image height 11.0000 11.0000 11.0000Overall length of 84.5038 98.6937 120.9891 lens system BF 14.2493530.01939 42.80595 d5 0.8000 12.4979 29.9184 d11 17.1604 5.9161 1.2471d13 2.2642 6.0270 3.8046 d17 7.7415 1.9449 0.9247

TABLE 25 (zoom lens unit data) Unit Initial surface No. Focal length 1 178.75066 2 6 −10.59398 3 12 27.01514 4 14 −2616.77566 5 18 31.91944

Numerical Example 7

The zoom lens system of Numerical Example 7 corresponds to Embodiment 7shown in FIG. 24. Table 26 shows the surface data of the zoom lenssystem of Numerical Example 7. Table 27 shows the aspherical data. Table28 shows various data. Table 29 shows the zoom lens unit data.

TABLE 26 (surface data) Surface number r d nd vd Object surface ∞  155.84490 1.20000 1.84666 23.8  2 36.51990 3.64760 1.62299 58.1  379.00430 0.10000  4 41.52110 3.72750 1.72916 54.7  5 127.00060 Variable 6 47.48680 0.70000 1.88300 40.8  7 9.21290 5.19790  8 −36.31510 0.700001.71300 53.9  9 22.54950 0.66020 10 17.65370 2.13660 1.92286 20.9 1170.50910 Variable  12* 49.20190 1.57590 1.62299 58.1  13* −25.66170Variable 14 ∞ 0.80000 (Aperture)  15* 8.98950 3.73580 1.60602 57.4 16−23.04640 0.60110 1.80611 40.7 17 10.79680 Variable 18 15.23920 2.959801.51680 64.2 19 −16.53070 0.47450  20* −319.44100 1.10000 1.84666 23.821 14.29310 2.63530 22 20.46790 3.82610 1.67270 32.2 23 −17.446100.70000 1.80420 46.5 24 ∞ BF Image surface ∞

TABLE 27 (aspherical data) Surface No. Parameters 12 K = 0.00000E+00, A4= 4.08440E−05, A6 = 1.16725E−06, A8 = 1.00452E−08, A10 = 0.00000E+00,A12 = 0.00000E+00 13 K = 0.00000E+00, A4 = 6.23327E−05, A6 =8.72583E−07, A8 = 1.27905E−08, A10 = 0.00000E+00, A12 = 0.00000E+00 15 K= 7.49904E−03, A4 = 2.87864E−07, A6 = −7.57882E−07, A8 = 1.85991E−08,A10 = −5.34654E−10, A12 = 0.00000E+00 20 K = 0.00000E+00, A4 =−1.32368E−04, A6 = −1.96725E−06, A8 = 1.78704E−08, A10 = −3.79119E−12,A12 = −1.04689E−11

TABLE 28 (various data) Zooming ratio 4.77533 Wide Middle TelephotoFocal length 12.2497 26.7697 58.4965 F-number 3.52073 4.69668 5.78910View angle 43.8136 22.0230 10.4393 Image height 11.0000 11.0000 11.0000Overall length of 73.5030 86.8070 107.4608 lens system BF 14.2515524.41954 35.64772 d5 0.8000 13.8560 28.6100 d11 15.7500 6.6380 1.5347d13 2.3871 3.7055 4.0618 d17 3.8361 1.7097 1.1283

TABLE 29 (zoom lens unit data) Unit Initial surface No. Focal length 1 176.11081 2 6 −11.08700 3 12 27.29203 4 14 −731.80378 5 18 31.94297

Numerical Example 8

The zoom lens system of Numerical Example 8 corresponds to Embodiment 8shown in FIG. 27. Table 30 shows the surface data of the zoom lenssystem of Numerical Example 8. Table 31 shows the aspherical data. Table32 shows various data. Table 33 shows the zoom lens unit data.

TABLE 30 (surface data) Surface number r d nd vd Object surface ∞  188.26400 1.20000 1.84666 23.8  2 43.50280 0.01000 1.56732 42.8  343.50280 4.99460 1.62299 58.1  4 413.57560 0.10000  5 39.72230 4.308301.72916 54.7  6 147.58050 Variable  7 38.98200 0.70000 1.88300 40.8  88.80120 4.94460  9 −23.63000 0.70000 1.83481 42.7 10 11.23190 0.010001.56732 42.8 11 11.23190 4.41630 1.86818 26.1 12 −15.50650 0.55940  13*−10.59640 1.00000 1.80470 41.0 14 −37.03350 Variable 15 48.84520 1.500001.66547 55.2  16* −28.64240 Variable 17 ∞ 1.50000 (Aperture) 18 12.114503.01020 1.48749 70.4 19 206.82520 0.01000 1.56732 42.8 20 206.825200.60000 1.80610 33.3 21 13.73900 Variable  22* 10.25290 3.64690 1.6060257.4 23 −35.72650 0.10000 24 35.21880 0.99980 1.83046 28.8 25 11.732405.70560 26 42.34090 6.03880 1.48749 70.4 27 −8.14660 0.01000 1.5673242.8 28 −8.14660 0.70000 1.80420 46.5 29 −51.32470 0.10000 30 38.674202.06170 1.84666 23.8 31 −187.37810 BF Image surface ∞

TABLE 31 (aspherical data) Surface No. Parameters 13 K = 0.00000E+00, A4= 7.39867E−05, A6 = 6.02754E−07, A8 = −2.24402E−08, A10 = 5.25424E−10 16K = 0.00000E+00, A4 = 1.84273E−05, A6 = 3.35332E−07, A8 = −2.88430E−08,A10 = 6.97520E−10 22 K = −1.12797E+00, A4 = 2.54429E−05, A6 =−9.39921E−08, A8 = 1.65281E−09, A10 = 0.00000E+00

TABLE 32 (various data) Zooming ratio 4.67743 Wide Middle TelephotoFocal length 12.4002 26.8121 58.0013 F-number 3.38665 4.60269 5.80130View angle 44.3351 22.0102 10.5448 Image height 11.0000 11.0000 11.0000Overall length of 81.1993 94.2455 115.1998 lens system BF 14.9473825.62181 37.54806 d6 0.3000 11.9797 24.2009 d14 10.7089 5.0772 1.1000d16 2.4246 2.4406 3.2246 d21 3.8922 0.2000 0.2000

TABLE 33 (zoom lens unit data) Unit Initial surface No. Focal length 1 160.94651 2 7 −8.55429 3 15 27.34279 4 17 −87.62354 5 22 22.54271

Numerical Example 9

The zoom lens system of Numerical Example 9 corresponds to Embodiment 9shown in FIG. 30. Table 34 shows the surface data of the zoom lenssystem of Numerical Example 9. Table 35 shows the aspherical data. Table36 shows various data. Table 37 shows the zoom lens unit data.

TABLE 34 (surface data) Surface number r d nd vd Object surface ∞  187.71220 1.20000 1.84666 23.8  2 42.95510 0.01000 1.56732 42.8  342.95510 5.00420 1.62299 58.1  4 369.62990 0.10000  5 39.91070 4.342701.72916 54.7  6 155.58550 Variable  7 37.02080 0.70000 1.88300 40.8  88.83250 5.00250  9 −20.42380 0.70000 1.83481 42.7 10 16.57920 0.010001.56732 42.8 11 16.57920 3.78010 1.84666 23.8 12 −15.28030 0.68100  13*−10.23960 1.00000 1.80470 41.0 14 −26.55310 Variable 15 45.43970 1.500001.66547 55.2  16* −30.07070 Variable 17 (Aperture) ∞ 1.50000 18 12.924201.86330 1.48749 70.4 19 346.37330 0.01000 1.56732 42.8 20 346.373300.60000 1.80610 33.3 21 15.30680 Variable  22* 12.36500 5.90880 1.6060257.4 23 −35.29670 0.10000 24 25.32620 1.00000 1.84666 23.8 25 12.404905.39410 26 77.10300 5.58810 1.48749 70.4 27 −8.12600 0.01000 1.5673242.8 28 −8.12600 0.70000 1.80420 46.5 29 −46.73290 0.10000 30 36.856601.98410 1.84666 23.8 31 −341.26400 BF Image surface ∞

TABLE 35 (aspherical data) Surface No. Parameters 13 K = 0.00000E+00, A4= 7.28351E−05, A6 = 7.45521E−07, A8 = −1.74222E−08, A10 = 3.98208E−10 16K = 0.00000E+00, A4 = 1.57549E−05, A6 = 8.54823E−07, A8 = −4.95846E−08,A10 = 9.77720E−10 22 K = −4.14123E+00, A4 = 2.08375E−04, A6 =−1.78708E−06, A8 = 1.16736E−08, A10 = 0.00000E+00

TABLE 36 (various data) Zooming ratio 4.67751 Wide Middle TelephotoFocal length 12.4001 26.8181 58.0015 F-number 3.39366 4.82419 5.80135View angle 44.3286 22.2858 10.5142 Image height 11.0000 11.0000 11.0000Overall length of 81.1832 93.3093 115.1803 lens system BF 14.9335227.81486 37.47430 d6 0.3000 9.4198 24.2385 d14 10.8135 4.5720 1.1000 d162.4012 2.3411 3.2012 d21 3.9461 0.3726 0.3774

TABLE 37 (zoom lens unit data) Unit Initial surface No. Focal length 1 161.06108 2 7 −8.58914 3 15 27.40972 4 17 −91.81665 5 22 23.53555

Numerical Example 10

The zoom lens system of Numerical Example 10 corresponds to Embodiment10 shown in FIG. 33. Table 38 shows the surface data of the zoom lenssystem of Numerical Example 10. Table 39 shows the aspherical data.Table 40 shows various data. Table 41 shows the zoom lens unit data.

TABLE 38 (surface data) Surface number r d nd vd Object surface ∞  1201.83550 1.20000 1.84666 23.8  2 66.61460 0.01000 1.56732 42.8  366.61460 4.93160 1.62299 58.1  4 −249.78590 0.10000  5 34.41100 4.283901.72916 54.7  6 80.13850 Variable  7 35.00000 0.70000 1.88300 40.8  88.70330 5.25180  9 −23.48370 0.70000 1.88300 40.8 10 33.38190 0.10000 1118.81810 3.47930 1.84666 23.8 12 −19.44510 0.39820 13 −14.82460 0.700001.80610 40.7 14 −147.35880 Variable  15* 111.29190 1.50000 1.66547 55.2 16* −31.23180 Variable 17 (Aperture) ∞ 1.50000 18 11.71290 2.903701.84666 23.8 19 8.08670 0.01000 1.56732 42.8 20 8.08670 1.57140 1.5180555.3 21 13.49630 Variable  22* 16.95600 3.26770 1.60602 57.4 23−26.94340 0.20000 24 32.29380 0.70000 1.84666 23.8 25 11.91580 0.010001.56732 42.8 26 11.91580 5.64970 1.60328 61.3 27 −9.89430 0.010001.56732 42.8 28 −9.89430 0.70000 1.77250 49.6 29 19.10340 4.48000 3035.06040 2.02760 1.84666 23.8 31 −284.69790 BF Image surface ∞

TABLE 39 (aspherical data) Surface No. Parameters 15 K = 0.00000E+00, A4= −8.51215E−05, A6 = 0.00000E+00, A8 = 0.00000E+00, A10 = 0.00000E+00 16K = 0.00000E+00, A4 = −6.08697E−05, A6 = −1.29115E−07, A8 = 1.22762E−08,A10 = −2.78378E−10 22 K = 1.81114E+00, A4 = −8.25524E−05, A6 =−2.20802E−07, A8 = −3.61059E−09, A10 = 0.00000E+00

TABLE 40 (various data) Zooming ratio 4.67735 Wide Middle TelephotoFocal length 12.3998 26.8163 57.9982 F-number 3.51704 4.95475 5.78611View angle 44.3687 22.0462 10.5177 Image height 11.0000 11.0000 11.0000Overall length of 81.7158 94.5908 113.6458 lens system BF 14.9662925.42375 35.49561 d6 0.3052 12.6295 25.7437 d14 12.1104 5.3002 1.1000d16 2.4896 3.8216 4.2216 d21 5.4594 1.0309 0.7000

TABLE 41 (zoom lens unit data) Unit Initial surface No. Focal length 1 162.89272 2 7 −9.16020 3 15 36.80232 4 17 270.40987 5 22 25.37175

Numerical Example 11

The zoom lens system of Numerical Example 11 corresponds to Embodiment11 shown in FIG. 36. Table 42 shows the surface data of the zoom lenssystem of Numerical Example 11. Table 43 shows the aspherical data.Table 44 shows various data. Table 45 shows the zoom lens unit data.

TABLE 42 (surface data) Surface number r d nd vd Object surface ∞  1103.95510 1.20000 1.84666 23.8  2 52.03290 3.50590 1.72916 54.7  3259.37390 0.10000  4 44.12290 3.31660 1.72916 54.7  5 138.91860 Variable 6 35.00000 0.70000 1.90366 31.3  7 9.09080 5.72300  8* −20.870401.10000 1.68966 53.0  9 25.47610 0.48520 10 20.61470 2.05620 1.9459518.0 11 222.90760 Variable  12* 43.00460 1.59480 1.66547 55.2  13*−28.28110 Variable 14 (Aperture) ∞ 0.80000 15 9.54420 3.66900 1.5168064.2 16 −28.87700 0.60600 1.80611 40.7 17 11.90270 Variable 18 12.927303.29950 1.48749 70.4 19 −19.14670 2.62610  20* −63.90600 1.10000 1.8466623.8 21 19.01980 4.45410 22 23.66820 2.78760 1.71736 29.5 23 −500.00000BF Image surface ∞

TABLE 43 (aspherical data) Surface No. Parameters 8 K = 0.00000E+00, A4= 6.10086E−06, A6 = −2.02053E−07, A8 = −2.99368E−09, A10 = 0.00000E+00,A12 = 0.00000E+00 12 K = 0.00000E+00, A4 = −1.33328E−05, A6 =5.11687E−07, A8 = 4.90565E−08, A10 = 0.00000E+00, A12 = 0.00000E+00 13 K= 0.00000E+00, A4 = 1.10487E−05, A6 = 9.31836E−08, A8 = 5.77089E−08, A10= 0.00000E+00, A12 = 0.00000E+00 20 K = 0.00000E+00, A4 = −1.39315E−04,A6 = −2.38804E−06, A8 = 4.02673E−08, A10 = −1.43563E−09, A12 =1.91908E−11

TABLE 44 (various data) Zooming ratio 4.70507 Wide Middle TelephotoFocal length 12.3694 26.8235 58.1992 F-number 3.56734 4.75407 5.78285View angle 43.4525 21.9127 10.5030 Image height 11.0000 11.0000 11.0000Overall length of 76.0039 89.4503 109.6387 lens system BF 14.2516625.64873 38.09690 d5 0.8000 12.2022 26.0988 d11 15.3235 6.3161 1.2987d13 2.3385 4.5843 3.8822 d17 4.1662 1.5750 1.1381

TABLE 45 (zoom lens unit data) Unit Initial surface No. Focal length 1 169.39989 2 6 −10.56381 3 12 25.86902 4 14 −80.77582 5 18 25.62722

The following Tables 46 to 48 show values corresponding to theindividual conditions in the zoom lens systems of the numericalexamples.

TABLE 46 (values corresponding to individual conditions: NumericalExamples 1 to 4) Numerical Example Conditions 1 2 3 4 (1) |f_(F)/f_(W)|1.88798 1.66143 1.81774 2.00011 (2) |f_(F)/f_(T)| 0.39539 0.353960.38602 0.42614 (3) |f_(F)/f_(NW)| 2.87284 2.03660 2.29831 2.52957 (4)β_(NT)/β_(NW) 1.89887 1.93201 1.98256 1.90850 (5) D_(F)/ΣD 0.079060.04868 0.04368 0.04252 (6) |f₁/f_(NW)| 6.94116 6.92872 6.70152 7.05231(14) D_(FWA)/f_(W) 0.16784 0.25970 0.24129 0.20781 (15) (D_(F)/f_(W)) *(f_(T)/f_(W)) 1.21716 0.73102 0.72949 0.61902 (16) |D_(F)/f_(F)| 0.135010.09374 0.08522 0.06594 (17) |f₁/f₂| 6.94116 6.92872 6.70152 7.05231(18) |f₂/f_(F)| 0.34809 0.49102 0.43510 0.39532 (19) |f₁/f_(F)| 2.416143.40211 2.91585 2.78795

TABLE 47 (values corresponding to individual conditions: NumericalExamples 5 to 8) Numerical Example Conditions 5 6 7 8 (1) |f_(F)/f_(W)|2.17154 2.18393 2.22792 2.20506 (2) |f_(F)/f_(T)| 0.46265 0.464180.46653 0.47143 (3) |f_(F)/f_(NW)| 1.45339 2.55005 2.46164 3.19642 (4)β_(NT)/β_(NW) 2.00911 1.89400 1.92207 2.08539 (5) D_(F)/ΣD 0.040730.03757 0.04376 0.03163 (6) |f₁/f_(NW)| 3.49113 7.43351 6.86494 7.12476(14) D_(FWA)/f_(W) 0.19999 0.18305 0.19487 0.19553 (15) (D_(F)/f_(W)) *(f_(T)/f_(W)) 0.59819 0.59289 0.61434 0.56582 (16) |D_(F)/f_(F)| 0.058690.05770 0.05774 0.05486 (17) |f₁/f₂| 3.49113 7.43351 6.86494 7.12476(18) |f₂/f_(F)| 0.68805 0.39215 0.40623 0.31285 (19) |f₁/f_(F)| 2.402062.91505 2.78876 2.22898

TABLE 48 (values corresponding to individual conditions: NumericalExamples 9 to 11) Numerical Example Conditions 9 10 11 (1) |f_(F)/f_(W)|2.21046 2.96793 2.09137 (2) |f_(F)/f_(T)| 0.47258 0.63452 0.44449 (3)|f_(F)/f_(NW)| 3.19118 4.01763 2.44886 (4) β_(NT)/β_(NW) 2.08253 2.151971.91320 (5) D_(F)/ΣD 0.03172 0.03342 0.04151 (6) |f₁/f_(NW)| 7.109046.86587 6.56965 (14) D_(FWA)/f_(W) 0.19365 0.20077 0.18906 (15)(D_(F)/f_(W)) * (f_(T)/f_(W)) 0.56582 0.56582 0.60664 (16) |D_(F)/f_(F)|0.05473 0.04076 0.06165 (17) |f₁/f₂| 7.10904 6.86587 6.56965 (18)|f₂/f_(F)| 0.31336 0.24890 0.40835 (19) |f₁/f_(F)| 2.22772 1.708932.68274

The zoom lens system according to the present invention is applicable toa digital input device such as a digital still camera, a digital videocamera, a mobile telephone, a PDA (Personal Digital Assistance), asurveillance camera in a surveillance system, a Web camera or avehicle-mounted camera. In particular, the present zoom lens system issuitable for an imaging device in a digital still camera, a digitalvideo camera or the like that requires high image quality.

Details of the present invention have been described above. However, theabove-mentioned description is completely illustrative from every pointof view, and does not limit the scope of the present invention.Obviously, various improvements and modifications can be performedwithout departing from the scope of the present invention.

1. A zoom lens system, in order from an object side to an image side,comprising: a first lens unit having positive optical power; a secondlens unit having negative optical power; a third lens unit havingpositive optical power; and an aperture diaphragm, wherein at the timeof zooming, the first lens unit, the second lens unit and the third lensunit move so that intervals between these lens units vary, wherein atthe time of focusing from an infinity in-focus condition to aclose-point object in-focus condition, the third lens unit moves to theimage side, and wherein the zoom lens system satisfies the followingcondition:0.15<D _(FWA) /f _(W)<0.30  (14) f_(T)/f_(W)>3.0 where, D_(FWA) is anaxial interval from the vertex of a surface on the most image side ofthe focusing lens unit to the aperture diaphragm, f_(T) is a focallength of the entire system at a telephoto limit, and f_(W) is focallength of the entire system at a wide-angle limit.
 2. The zoom lenssystem as claimed in claim 1, satisfying the following condition:0.50<(D _(F) /f _(W))*(f _(T) /f _(W))<1.50  (15) f_(T)/f_(W>)3.0 where,D_(F) is an axial thickness of the focusing lens unit, f_(T) is a focallength of the entire system at a telephoto limit, and f_(W) is focallength of the entire system at a wide-angle limit.
 3. The zoom lenssystem as claimed in claim 1, satisfying the following condition:0.02<|D _(F) /f _(F)|<0.15  (16) f_(T)/f_(W>)3.0 where, D_(F) is anaxial thickness of the focusing lens unit, f_(F) is a focal length ofthe focusing lens unit, f_(T) is a focal length of the entire system ata telephoto limit, and f_(W) is focal length of the entire system at awide-angle limit.
 4. The zoom lens system as claimed in claim 1,satisfying the following condition:3.00<|f ₁ /f ₂|<8.00  (17) where, f₁ is a focal length of the positivelens unit, and f₂ is a focal length of the negative lens unit.
 5. Thezoom lens system as claimed in claim 1, satisfying the followingcondition:0.20<|f ₂ /f _(F)|<0.80  (18) where, f₂ is a focal length of thenegative lens unit, and f_(F) is a focal length of the focusing lensunit.
 6. The zoom lens system as claimed in claim 1, satisfying thefollowing condition:1.50<|f ₁ /f _(F)|<4.00  (19) where, f₁ is a focal length of the lensunit having positive optical power, and f_(F) is a focal length of thefocusing lens unit.
 7. An interchangeable lens apparatus comprising: azoom lens system; and a camera mount section connected to a camera bodyprovided with an image sensor for receiving an optical image formed bythe zoom lens system and then converting the optical image into anelectric image signal, wherein the zoom lens system, in order from anobject side to an image side, comprises: a first lens unit havingpositive optical power; a second lens unit having negative opticalpower; a third lens unit having positive optical power; and an aperturediaphragm, at the time of zooming, the first lens unit, the second lensunit and the third lens unit move so that intervals between these lensunits vary, and at the time of focusing from an infinity in-focuscondition to a close-point object in-focus condition, the third lensunit moves to the image side, and the following conditions aresatisfied:0.15<D _(FWA) /f _(W)<0.30  (14) f_(T)/f_(W)>3.0 where, D_(FWA) is anaxial interval from the vertex of a surface on the most image side ofthe focusing lens unit to the aperture diaphragm, f_(T) is a focallength of the entire system at a telephoto limit, and f_(W) is focallength of the entire system at a wide-angle limit.
 8. A camera systemcomprising: an interchangeable lens apparatus that includes a zoom lenssystem; and a camera body that is connected to the interchangeable lensapparatus via a camera mount section in an attachable and detachablemanner and that includes an image sensor for receiving an optical imageformed by the zoom lens system and then converting the optical imageinto an electric image signal, wherein the zoom lens system, in orderfrom an object side to an image side, comprises: a first lens unithaving positive optical power; a second lens unit having negativeoptical power; a third lens unit having positive optical power; and anaperture diaphragm, at the time of zooming, the first lens unit, thesecond lens unit and the third lens unit move so that intervals betweenthese lens units vary, and at the time of focusing from an infinityin-focus condition to a close-point object in-focus condition, the thirdlens unit moves to the image side, and the following conditions aresatisfied:0.15<D _(FWA) /f _(W)<0.30  (14) f_(T)/f_(W)>3.0 where, D_(FWA) is anaxial interval from the vertex of a surface on the most image side ofthe focusing lens unit to the aperture diaphragm, f_(T) is a focallength of the entire system at a telephoto limit, and f_(W) is focallength of the entire system at a wide-angle limit.